But Dr. H. Wayne Carver II, the Connecticut chief medical examiner who conducted the analysis, said he doubts these results could explain the motives behind Lanza's deadly rampage, as his brain showed "nothing unusual."

Furthermore, results of the full toxicology exam — which involve testing body fluids for psychiatric medications or illegal substances — could take "several weeks." According to Dr. Carver, these results could provide "potential information" into the motives of the deadly shooter.